The slouch hat and the false queue were kicked into one corner. Ah Sin’s long, lean fingers were gripping Bob’s throat. There was no look of hate, or anger, or even of determination in the Chinaman’s face; the expression was blank and saturnine, as though he was merely a tool, operated by wires like a puppet and carrying out the will of some one in high authority.

Suddenly, putting forth all his strength, Ah Sin lifted Bob by the throat and threw him bodily across Speake and against the edge of the locker. Bob tried to rise, but found it impossible.

The awful weakness held him in thrall and was fastening gyves upon his wrists. Soon he would be utterly helpless, like those lying around him, and what would Ah Sin then do to the Grampus?

A spasm of alarm and apprehension rushed through the young motorist. Was this to be the end of the submarine’s voyage? Was the sale of the boat to the government destined never to be consummated?

Vaguely Bob thought of Captain Nemo, junior, lying sick in that house in Belize, of his unswerving confidence in the king of the motor boys, and of his tremendous disappointment if anything happened to the submarine during her daring cruise.

All this brought every ounce of Bob’s failing strength back to him. He shoved his hand along the side of the locker and twined his fingers about the grip of the revolver dropped by Glennie; then, with a despairing effort, he lifted himself on one elbow and again directed his gaze at the Chinaman.

Ah Sin had not been idle. He was holding something in his hand—a round object from which hung a long, black string. The Chinaman was lighting a match and touching the flame to the end of the string.

Bob could not see very distinctly, for everything in the periscope chamber, even the chamber itself, was reeling about him in fantastic lines.

The glow at the end of the black string sputtered and hissed. Stepping over to one corner, Ah Sin placed the round object on the floor with exceeding care, pulling out the string so that it lay in a straight line, the burning end pointed toward the center of the room.